DXM Tolerance And Dextromethorphan Potentiation

Last Updated: June 12, 2020

Dextromethorphan tolerance ensues when a person happens to take the drug constantly for a long time. Medication interacts with the brain chemistry of the brain, and in time, it can get used to the effects. People who refuse to deal with tolerance keep on finding ways to enjoy the high effects of DXM continuously. Dextromethorphan potentiation can be achieved through the help of other agents or paraphernalia.

How Does Dextromethorphan Tolerance Appear?

People often stumble into the pleasant sedation and body high associated with this medication by taking more than the recommended dextromethorphan dosage by weight or by age. While OTC dextromethorphan cough drops are generally safe, any other dextromethorphan products may lead to DXM tolerance, overdose, and other serious complications. Others intentionally take more significant amounts of this drug repeatedly for several reasons, thus developing DXM redose tolerance (especially when using dextromethorphan for pain relieving).

Tolerance to dextromethorphan occurs when a person experiences a reduced reaction to a drug. The body and the brain have been acclimatized with the drug and no longer respond to it the same way as when it was first used. This results in users needing to administer higher doses of DXM to achieve the desired effects.

Knowing how long it takes to build up a tolerance to DXM can help an individual avoid getting used to the drug. However, DXM tolerance timeline may differ from one person to another. Several factors may affect how fast one can build a tolerance to DXM, and these include:

  • The age and weight of the patient. While DXM LD50 has been established, genetics will still play a huge role
  • The drug form used. For example, how much DXM is in Delsym can greatly affect metabolism and the development of tolerance. This specific form contains polistirex as its active ingredient, which is time-released. Its effect can last for up to 12 hours, making it more potent when used recreationally
  • The period of consumption
  • User’s expectations for the drug
  • The environment where the individual consumes the drug
  • The overall level of tolerance to other medications
  • Potential drug interactions with psychoactive drugs like when combining DXM and Adderall

While individual factors may still play a role in how long for DXM tolerance to go down, it generally takes about 3 to 7 days for the tolerance to be reduced by 50%. It can be back at baseline within a week or two, provided that there is a complete DXM tolerance break or no further consumption.

DXM Tolerance Symptoms

The following symptoms can indicate that a person has developed tolerance to this medication:

  • The person needs to increase the dosage every time.
  • The effects of dextromethorphan wear off rapidly.
  • Dextromethorphan craving is evident in between doses.
  • Some signs of withdrawal appear once the drug effect fades away.

dxm tolerane causes mood swings

To know if someone has developed tolerance to DXM, watch out for the following signs and symptoms:

  • Unexplained change in personality
  • Mood swings, irritability, or angry outbursts
  • Unexplained financial problems
  • Engaging in secretive behaviors
  • Periods of hyperactivity and giddiness
  • Possession of too many prescriptions

Dextromethorphan Potentiation

When the effect of dextromethorphan is reduced, users still often look for ways to enjoy the high effects of the drug and keep DXM tolerance low. People use other drugs or agents to yield a better pharmacologic response:

  • One of the most popular ways to potentiate DXM effects is the use of grapefruit juice. Grapefruit juice enhances the effect of dextromethorphan by increasing its bioavailability. This is done by down-regulating a specific subfamily of the cytochrome P450 enzyme, which the major catalyst involved in dextromethorphan metabolism. Seville orange juice works the same way too.
  • Others use diphenhydramine (PH) to potentiate this medication and to get rid of some side effects like “robo-itch” and nausea. DPH also inhibits enzymes in the liver, thus making more dextromethorphan available into the bloodstream.
  • In Ayurveda, black pepper is a known bioavailability enhancer. It enhances the activity of DXM by increasing bioavailability across cell membranes. It can likewise potentiate the drug molecules by acting as receptors, making target cells more receptive to DXM. Users have used black pepper to potentiate the effects of dextromethorphan.

black papper for dxm potentiation

  • Some users also report that mix of dextromethorphan with alcohol can enhance the trip and prevent nausea. Cannabis and nitrous oxide can do this too. Dextromethorphan is a CNS depressant that may cause drowsiness and euphoria. Alcohol also has similar effects, but mixing them can be very dangerous because of side effects and risk of overdose on DXM increases. One may suffer from respiratory depression, dissociation, epilepsy, emotional and behavioral changes, memory loss, cognitive impairment, and even death.
  • Smoking of DXM HBr in the form of pure powder or crystals is also a common practice. It bypasses the first-pass metabolism in the liver, thus delivering more concentrated drugs in the system. The fast delivery of the drug to the brain is also one of the main reasons why smoking drugs is very popular.
  • Listening to music is one of the most interesting things to do while on this medication, especially at lower doses. It is enjoyable and relaxing, and will often induce dextromethorphan visuals and hallucinations. Others do dancing, swimming, and group tripping.

How To Get Rid Of Dextromethorphan Tolerance?

Finding another cold and cough medicine is one way to start a DXM tolerance reversal. People who had chronic use of dextromethorphan are likely to experience withdrawal symptoms, so tapering down the dosage while slowly reducing DXM tolerance can help.

In some cases, discontinuing the use of the drug for some time can lead to a DXM tolerance reset. Others go through detoxification and supportive therapies like behavioral counseling. Treatment to target possible withdrawal symptoms while tapering the doses may also help.

Using DXM after tolerance break will allow one to start at baseline, but relapse is always possible.

From DXM Tolerance To An Addiction

Habitual users who had an escalating tolerance DXM may develop an addiction. Instead of conducting a DXM reverse tolerance, most people tend to increase their intake until their body starts craving for more. Young people, ages 12-20, account for 51% of ER visits for nonmedical use of dextromethorphan due to several side effects like dextromethorphan diarrhea. Approximately 33-50% of people who experiment with dextromethorphan develop tolerance and go on to abuse it regularly. A dextromethorphan urine test can help confirm drug use.

The tolerance which is caused by DXM class of drug may be turned into an addiction. It will require immediate medical intervention from experts in drug rehab facilities. Proper substance abuse treatment options will help people address the problems that drive their behaviors, rectify these issues, learn coping skills, and develop a long-term plan for sobriety.

Page Sources

  1. Di Marco MP, Edwards DJ, Wainer IW, Ducharme MP. The effect of grapefruit juice and seville orange juice on the pharmacokinetics of dextromethorphan: the role of gut CYP3A and P-glycoprotein. 2002. https://www.ncbi.nlm.nih.gov/pubmed/12095536
  2. Kritika Kesarwani, Rajiv Gupta. Bioavailability enhancers of herbal origin: An overview. 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3634921/
  3. Clinical and Research Institute on Addictions Ria Expert Summary. DXM (Cough Suppressant) Abuse. 2013. http://www.buffalo.edu/cria/news_events/es/es7.html

Published on: August 6th, 2019

Updated on: June 12th, 2020

About Author

Peter J. Grinspoon, MD

Dr. Peter Grinspoon is an experienced physician with long-term clinical practice experience. As a former analgesic addict, Dr. Grinspoon knows precisely how important it is to provide patients with effective treatment and support. Medical writing for him is the way to communicate with people and inform them about their health.


Leave a comment